Unsolicited telemarketing calls have been identified by the Canadian and American governments as a serious problem, as is evident in the fact that both countries have initiated the implementation of national ‘do not call lists’ (DNCL). Presently there are no regulations in place to curtail telemarketing and other unsolicited telephoning activities. Even if and when such rules are implemented, there will be numerous proposed exceptions to telemarketing rules that will allow charities, political parties, polling companies, businesses with existing business relationship, and others to telemarket to those listed on the DNCL. In addition to those entities who will still be allowed to call numbers registered on the DNCL, there will likely still be noncompliant telemarketers who call numbers listed on the DNCL.
Several means of screening and/or blocking unwanted calls, such as telemarketing calls, currently exist. For example, some telecommunications companies offer call-blocking services which allow subscribers to manually manage all calls from specific callers or category of calls (e.g. all 900 calling codes, all toll-free codes, or all calls where caller identification information is unavailable) that the subscriber identifies. The limitation of such call-blocking services is that they are static lists with little or no exclusion capabilities and may only capture a fraction of the telemarketing calls; the blocking parameters have to be determined in advance; and they may prevent desired calls from reaching the recipient.
There are electronic devices on the market which automatically remove the assigned telephone number of the receiving line from computer dialed telemarketing call-lists, by sending a tone when the user picks up the call that falsely indicates to the calling computer that the number is disconnected, so the computer deletes the phone number. This solution does not spare the user from the disturbance of the call, as the call must be answered in order for the device to take effect, and is limited to computer-initiated telemarketing calls. Also, each user cannot take advantage of the experience of other users.